Nebulizing inhalator for medication



Dec. 16, 1941. s. L. Fox ET AL NEBULIZING INHALATOR FOR MEDICLXTIO?.T

Filed May 19, 1957 Frei. I

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A is dilcult for the user,

Ywithout extremely Patented Dec. 16, 1941 UNiTED STATES A NEBULIZINGINHALATOR FOR MEDICATION Stanley L. Fox and `Charles C. Coghlan, LosAngeles, Calif.

Application May 19, 1937, Serial No. 143,511 3 Claims. (Cl. 12S-194) Ourinvention relates to an inhalator for a liquid medicament in which suchmedicament in a partially or completely atomized or vaporized form isdrawn into the mouth, throat or lungs or the nasal passage during theinspiration. v 5 There have been a number of instruments devised andused which attempt to apply a liquid medicament in this finely dividedform on the air ejector principle in which air is forced under pressurepast the end of an aspirating tube or the ,10 like which dips into theliquid medicament. A disadvantage of any type of instrument of thislatter character resides partly in the fact that it designated thepatient, to judge accurately the pressure and the flow of air V1,5necessary to secure a proper atomizing or vaporizing ofthe medicament.Another disadvantage is that if an application of the medicament is madeto the mouth, throat or lungs or to the nasal passages through aninvoluntary reaction against inblown air with the vapor and tends toresist drawing this into the throat or lungs or the nasal passages. Evenif medication by such a device is administered by a doctor or a nurse,it is difficult for them to25 judge the pressure oi air necessary andthefff' amount of air flow which should be developed to give a properatomizing spray timed with inspiration so that the medicament may beapplied internally in the desired manner. Most of thei devices operatedby a pressure air flow utilize a"Y rubber expansible and contractablebulb as a pump but even if the medication is administered by such meansin the hands of the nurse, the patient involuntarily reacts againstentrance of the atomized stream and thus their medicament is notproperly carried and distributed to the place desired. This particularlyapplies to any applications of a medicament to the lungs or to thethroat.

A main object therefore of our invention re-tV sides in an inhalator inwhich during the inspiration oi the breath the patient may draw in bysuction the desired liquid medicament either in a partially orcompletely vaporized form by in- 45 haling through the mouth or thenostrils. Thisl action creates an air ilow by suction through theinstrument so that the action is developed by the inflow of air over theend of the aspirating tube extending into the liquid medicament anddraws 50 a minute jet of the liquid into the air inhaled because of thenegative pressure developed. This causes the fine atomizing orvaporizing of the liquid medicament so that only a vapor with or minuteparticles or globules is liliv vinto the air flow. The

the nose, the patient has 20' c passage of air the forcible, c v-35drawn into the mouth, throat or lungs or into the nasal passages. Allthe air taken in through the instrument during an inhalation comes inintimate contact with the nely atomized medicament giving asubstantially larger concentration than possible by any other means.

A characteristic of our invention resides in part in providing arelatively large space or area for the inflow of air under suction ofinhaling in breathing, tapering such opening toward one or more smallorices from which the air enters the jvaporizing chamber at relativelyhigh velocity.

This is suiiicient when passing over the open jet end oi a tubeextending into the liquid to cause a ne jet or stream of the liquid tobe ejected action of the relatively high velocity flow of air undersuction and the much slower velocity flow of the liquid through the finetube causes an initial breaking up or atomizing of the liquid, thisproducing the socalled nebulizing effect. As the Whole action iscontrolled by Voluntary inspiration the user or patient thus has adirect control of the amount of vapor which will be drawn into the mouthor through the nose. Thus when it is desired to treat the throatbronchial tree or lungs with a medicament, the act of inhaling draws ina suicient amount of air and at the same time atomizes and vaporizes theliquid and causes its even distribution in the nose, or throat,bronchial tree and lungs. After the initial nebulization furthervaporization of the liquid occurs from the stream over the surfaceswhich expose the fluid to such action as well as from the expansion ofthe air vapor and globules as it passes the Venturi throat or baiiies,such action being mainly in the upper or dome part of the instrument.

Our invention is illustrated in connection with the accompanyingdrawing, in which:

Fig. 1 is a vertical section which may be considered as taken on thevertical section line l I--I of Fig. 2 in the direction of the arrows.

Fig. 2 is a horizontal section on the line 2-2 of Fig. l in thedirection of the arrows.

Dealing with the construction of Figs. 1 and 2,

y in our invention we employ a medicament reservoir structure II whichincludes a cylindrical tube I2 having at the bottom a thickened collarI3 with a cone shaped Wall I4 extending upwardly having a horizontalupper end I5. This is provided with a plurality of small air intakeports I6, four of these being illustrated. The

. air passing through these ports operates on the ejector principletodraw liquid through the small bore tubes I'I which have a jet end I8preferably formed beveled. These tubes are attached by a cementedconnection I9 to the upper end I5 of the conical bottom or base I 4. Thelower end 20 of each tube is provided with an opening 1ocated inproximity to the angle formed by the cone shaped bottom I4 and acylindrical outer wall I2. There is thus provided an annular reservoir2| for the medicament. The liquid in this should always be below the topof the transverse portion I of the bottom. A distributing tube 25 has acylindrical lower section 26 with .a threaded connection 21 to the upperend of the tube I2. Tube 25 has a contracted neck 28 forming a Venturitype of throat 29. An upper cylindrical section 30 terminates with aclosed dome 3l. AnV

air suction pipe 33 leads through the dome and preferably has a beveledend 34 with the bevel extending upwardly and thus having the lowerportion somewhat pointed as indicated at 35 extending well beyond theaxial center of the tube sections 26 and '36 and the Venturi formingsection 28. This produces an under-surface 36 of the suction air tube onwhich globules of liquid may collect and condense. Preferably flexiblepipe or tube 3l is connected to the outer end of the xed pipe 33 andthis may have a suction end piece for inserting in the mouth orconnecting to either or both of the nostrils.

Although the device may be used as above described, however, we preferto have the air intake through a flutter valve construction designatedby the assembly numeral 40. This employs a cyiinder 4I having a threadedconnection at 42 to the thickened collar section I3 at the lower part ofthe reservoir. At the lower end of the cylinder there is an annularvalve seat 43 leaving a circular valve opening or port 44. A disc-likeflutter valve 45 is seated on the annular seat 43 and is maintainedpressed downwardly by a coil compression spring 46 which bears at itsupper end against the end of the collar I3 of the upper part of theinstrument and at its lower portion on the valve disc 45.

The operation of the device including the flutter valve is as follows:It will be understood that on account of the threaded connection at 42 aslight adjustment may be made as to the compressible action of thespring 46. Thus when the flutter valve construction is slightlyunthreaded the spring pressure is less'than when the threaded connectionis made tight. This gives a slightly variable action in the fluttervalve. After the instrument has been filled to the proper level with themedicated liquid which may be either poured through the iixed pipe 33 ormay be inserted after unthreading the connection at 21, then when air issucked into the mouth or nostrils through the pipes 31 and 33, duringinspiration of the breath, a partial vacuum is created in the relativelylarge chamber in the distributing tube 25. This, on account of the openport I6 likewise produces a partial vacuum above the flutter valve discand causes this to raise, allowing inflow of air. On account of therelatively large area the velocity of flow of this air is comparativelylow, however on account of the Vconverging air path due to the conicalbottom I4, the velocity is increased and the air flows through the portsI6 at a relatively high velocity. This causes an ejector action 'inregard to the liquid in the annular reservoir 2l, such liquid beingdrawn up through the small bore tubes II and as the jet openings I8 aredirectly over the center of each air port 75 I6, globules of the liquidare immediately carried oiT by the inflowing air stream developed bysuction. This action causes an atomizing of the liquid producing anebulous type of vapor. In the formation of the vapor if the air suctionis too great small globules of the liquid are carried upwardly, that is,in part impinge on the contracted throat portion 28 and ow downwardly onthe inside wall of the distributing tube 25 and thus iiow into thereservoir 2I. However, due to the Venturi type action of the contractedthroat 29, a relatively high velocity is produced through this throat.This brings the air into intimate contact with the minute globules ofliquid which have been elevated against the force gravity and causesthese to be broken up in the -air stream into more minute particles. Inaddition the crowding action of the air flow with the Vliquid pas-singthrough th'e Venturi type of throat brings the larger globules intocontact with the lower portion of the neck 28 and these globulesflowdownwardly on the cylindrical portion 2S and the wall Istructure 'I2into the reservoir 2|.

An additional actionof distribution takes place in the upper portion 36of the tube 25 as above the Venturi throat to an expansion of theupwardlyflowing air. This tends to allow separation of any largeglobules of liquid. Some of these Vcome in contact with the wall 30 andiiow downwardly. Other large globules strike the under portion 36 oi thetube 33 and as the beveled inner end 34 slopes upwardly the vaporspassing through the tube '3 are very nely atomized and practicallywithout any large globules of liquid. Thus `the liquid medicament isgiven a more even spread on entry in the mouth or through the 'nasalpassages. T'he action of the utt'er valve is to allow entry of aquantity of air, this ,acting against the compres-sion of the spring'46. The spring then reacts to close the valve which again opens whenthe vacuum inside the instrument increases. Thus 'there is yanintermittent inflow of the air which develops an improved action of theejector in elevating the liquid from the reservoir and in the atomizingof such liquid. However it is to be understood that if desired theflutter valve construction may be removed from the instrument Aor theinstrument may be made without provision for attaching such valve inwhich case the air ilo-ws inwardly through the relatively large annularcollar IS3.

The chamber above the throat or Venturi construction of Fig. 1 acts asan expansion chamber in which ,liquid globules may condense, some oftheser contact the wall and are then subjected to an evaporati-ng actiondue to the air passing over such small globules. The action ofvaporization of the liquid medicament by the suction which creates aminus pressure is one of slight refrigeration in which the air entering`the mouth or nostrils is slightly cooler than the air flowing inthrough the instrument. Therefore it will vbe understood that where ahot or warm application of medicament is desired that the air .may beheated blefore being drawn into the instrument by ysuction or as is amore or less common practice, there may be an intermediate chamberbetween the patient and the inha-lator, the patient :by suction drawingthe air Vand medicament ythrough such intermediate chamber which may-be.heated to apply hot .applications. Where-cold applications arerequired,

manifestly 'this intermediate chamber could be chilled. In some cases itis also desirable to have a washing action of certain medicanfents bybubbling the air through water or other washing solution contained in anintermediate chamber. The action of the flutter valve is tointermittently increase the vacuum and thus lassist in vaporization ofthe liquid, hence increasing the concentration of the medicament in theair stream.

The method of operation of our inhalator involves the creation of apartial vacuum or negative pressure in the hollow body structure solelyby air inspired in breathing either through the mouth or nostrils. Thiscreates a positive air flow from the' outside atmosphere which operateson the liquid medicament in the reservoir. By providing the small boreejector tube or tubes, the partial vacuum created in such tubes by theflow of air thereover on the operation of suction creates the positiveelevation of the liquid from the reservoir into the air stream. At firstthe liquid leaves these small bore tubes in the form of small globulesproducing an atomized effect. As these globules come in contact with theair flowing at different velocities and the more or less turbulence ofthe air as well as by impinging on the sides of the body structure, theybecome broken up and form a medicated vapor which on being drawn intothe mouth or nostrils and on the further inhalation will operate tocarry the medicament to the mouth, nasal passages, the throat, bronchialtree and lungs. Thus the sole act of inhaling changes the form of theliquid carrying the medicament into an atomized and vaporized form.

An important characteristic of our invention resides for instance as tothe construction of Fig. 1 in providing an annular reservoir with thebottom of the inhalator having an upwardly sloping wall, this being thewall I4 which is cone shaped. Such provides a relatively large openingor channel for the inflow of air which air enters through the pluralityof small ports I6. As these ports are located in the upper horizontalend I5 of the bottom structure they may be located but slightly abovethe level of the liquid in the reservoir therefore the small boreinjector tubes I1 may have their orice or jet end I8 positioned butslightly above the liquid. Therefore on the inflow of air enteringthrough the plurality of ports it is only necessary that the liquid beelevated by suction a comparatively short distance. This produces aplurality of atomized streams of the medicated liquid and these streamsmingle together, the medicated vapor thus being taken by the patientthrough the mouth or through the nose into the bronchial tract andlungs. In cases where the patient finds difiiculty in breathing, thatis, inhaling, the flutter valve assembly 40 may be removed.

Our invention is particularly valuable in treatment of patientsafflicted with asthma of the type which causes difficult breathing. Withsuch patients inhalation is not only difficult but tires the muscles ofthe diaphragm and accessory breathing muscles, therefore it is necessaryto give the relief with as few inhalations as possible. With ourinvention a medicament may be used in solution with the water which ispractically no more volatile than the water itself and thus themedicament has the characteristics of being a mild drug and on accountof the construction of the inhalator, at each inhalation there is themixing of the plurality of jets or CIA streams of the atomized waterwith the liquid medicament. In most of the inhalators patented or now onthemarket, insufficient provision is made for operation by inhalation bythe patient and hence it is customary with such devices to use readilyvolatile solutions of the medicament and these are too potent and Vtooirritating and toxic to the lungs andother tissues reached through themouth and nostrils.

Various changes may b e made in the details of the construction withoutdeparting from the spirit or Vscope of the invention as defined by theappended claims.

We claim:

l. An inhalator comprising in combination a hollow body structure havinga large air flow channely at the bottom with a wall extending inwardlyand upwardly from the bottom and provided with a thin top wall at theupper end of saidr channel, such wall having a plurality of small airinlet ports of short length with their axes parallel and directedparallel to the longitudinal center of the hollow body structure, saidupwardly extending Wall and the lower portion of the body structuredefining an annular reservoir for a liquid medicament, and an injectormeans having a jet orifice positioned above and in alignment with eachport with an intake for liquid extending downwardly to dip-in thereservoir, the upper part of the hollow body having an inhalationsuction means to be operated solely by inhalation through the mouth ornostrils, such inhalation creating an upward flow of air through thechannel at the bottom, the velocity of the air through the channelincreasing towards the top and further developing a fine stream of airthrough each inlet port directed upwardly and parallel one to the other,the velocity of flow through each port being much higher than thevelocity in the channel, the ow of air through the ports developing anejector action at each ejector orifice causing an atomizing of theliquid medicament in a plurality of upwardly flowing parallel streams,such streams being adapted to mix in the upper part of the hollow body,such medicament being carried upwardly with the flow of air to beinhaled through the mouth or nostrils into the bronchial tract and lungsproducing a local as well as a systematic reaction by absorption intothe blood stream, a flutter valve device connected at the bottom of thehollow body structure and below the entrance end of the air flowchannel, such flutter valve device having a valve opening with a valveseat and a flutter valve disk, a compression spring seating the disk onthe seat adjacent the opening, the spring being tensioned to maintainthe utter valve closed until a desired degree of vacuum is created inthe hollow body structure, such vacuum by producing a negative pressurefacilitating the vaporization of the liquid, the spring having thecharacteristic of yielding at a higher degree of vacuum and admittingair to carry the evaporated liquid to the inhalation suction means andthen on the increase of internal pressure the spring again closing theflutter valve and during inhalation developing an intermittent action ofopening and closing the valve.

2. An inhalator comprising in combination a hollow body structure havingone or more inlet air ports, the bottom of the structure forming areservoir for a medicament, an ejector means having a jet orificepositioned in alignment with the port or lports and having an intake endextending into the reservoir, an air suction outlet constructionconnected to the bottom of the body structure and having a spring closedvalve operative to open on a partial vacuum being created in the hollowbody structure by inhalation and to close when the internal pressure isincreased and thereby develop an intermittent Opening and closing of theflutter valve during a continuing inspiration through the suctionpipe.

3. An inhalator comprising vin combination a closed hollow bodyvstructure having an air ilow channel at the bottom including a `Wall atthe upper end of such channel, an air port extending through such wall,there being a reservoir below the said wall for a liquid medicament, aninjector means having a jet orifice positioned above and in alignmentwith the por-t with an intake for liquid in the reservoir, the upperpart of the hollow body having an inhalation suction means to beoperated solely by inhalation through the mouth or nostrils, a -uttervalve device connected yremote from the port and orifices, a fluttervalve at the bottom of the hollow body structure and below the entranceend `of the air flow channel,

such iiutter valve device having a valve opening with a valve seat and aflutter valve disk, a compression spring seating the ,disk on the seatadjacent the opening, the spring being .tensioned to maintain the uttervalve closed until a desired degree of vacuum is created in the hollowbody structure, such vacuum by producing a negative pressurefacilitating the vaporization of the liquid, the spring having thecharacteristic of yielding at a higher degree of vacuum and admittingair to carry the evaporated liquid to the inhalation suction means andthen on the increase of internal pressure the spring again closing theflutter valve and during inhalation developing an intermittent action ofopening and closing the valve.

STANLEY L. FOX.

CHAS. C. COGHLAN.

